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24 The University of Kansas Paleontological Contributions—Paper 99 Fig. 5. Elements of Fryxellodontus inornatus Miller with line drawings of basal cavities and transverse sections; all from Signal Mountain Limestone, Wichita Mountains, Oklahoma; 472m (1,546 ft) above base of Chandler Creek section of Stitt (1977). A. Lateral stereophotos (A,A ') and drawings (A ",A " ') of planar element, USNM 303410. B. Lateral stereophotos (B,B ) and drawings (B ",B ' ) of serrate element, USNM 303411. C. Lateral view (C) and drawings (C ',C") of intermediate element (posterior), USNM 303412. D. Lateral view (D) and drawings (D ',D") of symmetrical element (posterior), USNM 303413. Black area on each transverse section shows position of prominent ridge. All X120. onomic stability of the species, I here designate one intermediate element from the typeseries (Miller, 1969, pl. 65, figs. 17-19, UW 1306) as a lectotype. When I described this species only the symmetrical, intermediate, and serrate elements were known, but I have subsequently discovered planar elements with the characteristic linear ornamentation of this species. This element is found throughout the Fryxellodon tus inornatus and Clavohatnulus elongatus Subzones of the Cordylodus pro-
Miller-Some Upper Cambrian and Lower Ordovician Conodonts 25 avus Zone (Fig. 1), whereas the other elements occur only from the base of the C. elongatus Subzone to the base of the overlying Hirsutodontus simplex Subzone. Lindstrom (1973, P. 79, 83) suggested that F. lineatus might be a junior synonym of F. inornatus; however, after studying much new material, I am convinced that both species warrant recognition. Besides having distinctive linear ornamentation, most of the elements of the F. !Meatus apparatus have a shorter stratigraphic range than do those of F. inornatus. Also, the apparatus of F. lineatus has a smaller proportion of planar and serrate elements. Occurrence. -F. lineatus occurs only in the United States, where it is known from Utah (upper Notch Peak and House limestones, House Range; Miller, 1969, 1978), South Dakota (upper Deadwood Formation, Black Hills), Oklahoma (upper Signal Mountain Limestone, Wichita Mountains), Texas (upper San Saba Member of Wilberns Formation, Llano uplift), New York (upper Whitehall Formation; J. E. Repetski, pers. commun.), and Missouri (upper Eminence Dolomite; V. E. Kurtz, pers. commun.). Genus HIRSUTODONTUS Miller, 1969 Type species. - Hirsutodontus hirsutus Miller, 1969, p. 431; by original designation. Discussion. -I follow Jones (1971, p. 56) and consider Strigaconus Druce and Jones, 1971, to be a junior subjective synonym of Hirsutodontus Miller, 1969. The apparatus of Hirsutodon tus consists of one form of element. HIRSUTODONTUS HIRSUTUS Miller Figure 4N; Plate 2, figure 14 Hirsutodontus hirsutus Miller (part), 1969, p. 431, text-fig. 41, pl. 64, figs. 25, 26, 29-31 (not figs. 27, 28, 32-35); not Jones, 1971, p. 56, pl. 7, figs. 7, 8; LindstrOm (part), 1973, p. 119.2, 121 (not p. 119.3). Emended diagnosis. -Ornamentation consisting of small nodes, large spines lacking. Discussion. - Species of Hirsutodontus can be distinguished from each other by differences in cusp length and ornamentation. H. hirsutus has a well-developed cusp and small nodes, whereas H. simplex has much larger spines. H. rarus has many tiny spines and a poorly developed cusp. H. lenaensis has small nodes distributed over all of the small, blunt cusp and is most similar to H. lzirsutus, which differs by usually lacking nodes on the posterior. Jones (1971) and LindstrOm (1973) synonymized Strigaconus simplex Druce and Jones, 1971, with Hirsutodontus hirsuttis Miller, 1969; however, E. C. Druce and I jointly realized that although the genera are synonyms, holotypes of the respective species are not elements of the same species. The nodose H. hirsutus occurs throughout the Cordylodus proavus Zone in the United States, whereas the spiny H. simplex is found only in the two upper subzones of the C. proavus Zone (Miller, 1978). Accordingly, spinose elements figured by Miller (1969, pl. 64, figs. 27, 28, 32-35), Jones (1971, pl. 7, figs. 7, 8) and Lindstrom (1973, p. 119.3), which were assigned to H. hirsutus, are reassigned to H. simplex. Occurrence. -H. hirstitus, as emended, occurs only in North America, and is known in Utah (upper Notch Peak and lower House limestones, House Range; Miller, 1969, 1978), Nevada (Whipple Cave Formation, southern Egan Range), South Dakota (upper Deadwood Formation, Black Hills), Oklahoma (upper Signal Mountain Limestone, Wichita Mountains), Texas (upper San Saba Member of Wilberns Formation, Llano uplift), New York (upper Whitehall Formation; J. E. Repetski, pers. commun.), and Alberta, Canada (Survey Peak Formation; Derby, Lane, & Norford, 1972). HIRSUTODONTUS LENAENSIS Abaimova Hirsutodontus(?) lenaensis Abaimova, 1971, p. 79, text-fig. 5, pl. 10, fig. 11; 1972, textfig. 1; 1975, p. 73, text-fig. 7.4, 7.5, pl. 6, figs. 1-3; Lindstrom, 1973, p. 118, 119.4, 123. Discussion. -I have not seen elements of Hirsutodontus lenaensis, but illustrations show them to be morphologically distinct (see discussion under H. hirsutus). The species is
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